The present invention relates to installation of optical components in an optical device, and more particularly to installation of several optical components with predetermined positional relations on the optical device.
In an optical device such as a light scanning device, various optical components must be seated at their positions with a predetermined positional relationship with high accuracy.
Conventionally, each of optical components is independently installed on the device by using appropriate fixing means. In such an installation method, it is inherently required to finish installations of all the optical components with corrections of astigmatism of the seated lenses and so on. It should be noted, however, that fine adjustment of each optical component, after all the optical components are installed, becomes complicated and time-consuming, since there is no sufficient working space for fine adjustment of each optical component.
Especially, in a light scanning device such as a laser beam scanning device employed in a laser printer and so on, a first lens for correcting scanning speed of light deflected by a deflection means on a scanning surface, and a second lens for correcting astigmatism of the first lens which may cause by manufacturing errors of the first lens and/or tilt of the surface of the deflection means, and so on are employed. In order to place the second lens at a position where it completely works to correct the tilt of the surface of the deflection means, the position of the second lens with respect to the first lens must be finely adjusted after other optical components including the first lens are fixed on the scanning device. As explained above, it is troublesome and time-consuming work.